Maintain and provide for the care and breeding of genetically defined rabbits (approximately 600 past the age of weaning). House rabbits in cage meeting Government requirements and provided by the Government. The rabbit shall be fed, watered, and receive routine care and bedding changes from a staff of animal technicians experienced in handling small animals. Breed rabbits according to detailed plans (provided by the NIAID) in 15-20 breeding groups to produce at least 500-600 weaned rabbits per year in 100- 150 litters. Conduct additional breeding of rabbits whose litters do not survive to weaning. Breeding protocols shall include operator assisted natural service, artificial insemination, and fostering procedures as needed. Conduct immunologic experiments under the direction of the Project Officer or his designees and perform routine procedures, including injections (approximately 1,500 per year) by intravenous, subcutaneous, intramuscular, and other routes as requested. Provide holding facilities, routine care, and technical support for approximately 360 Specific Pathogen Free (SPF) rabbits. These rabbits shall be held separate from the genetically defined and other rabbits to minimize the opportunity for exposure to pathogenic agents. Separation of the specific-pathogen-free colony and the conventional (genetically-defined) colonies must be continued to minimize the opportunit for disease organisms to be transferred between the two groups of animals. Rabbits in both colonies must be bred according to directions received from the Project Officer or his designees. Particular attention must be given to providing genetically defined rabbits when needed. In addition the Contractor must continue to provide technical support (bleeding, immunization, organ harvest, delivering animals and animals products) to NIAID scientists utilizing the facilities at Spring Valley Laboratories.